Captcha - Preventing Pressing Back To Retry Captcha
Found that in some cases if a user presses back, then our captcha solution would redisplay the image. This would potentially allow a user to retry the same captcha over again which for security reasons would be bad. Placing these in the Load section of the page seems to have removed that issue.: Response.AppendHeader("Cache-Control", "no-cache, no-store, must-revalidate") 'HTTP 1.1. Response.AppendHeader("Pragma", "no-cache") 'HTTP 1.0. Response.AppendHeader("Expires", "0") 'Proxies. http://stackoverflow.com/questions/49547/how-to-control-web-page-caching-across-all-browsers/2068407#2068407